To
get caught up on the latest research on the global food system and water crisis
we did a survey of the must-read articles from the last twelve months. The requirements to make our list were
simple. First, the article had to be
from the Research Articles or Reports sections of Science or the Review,
Articles, or Letters sections of Nature published between May 2011 and April
2012. Then we picked the ones that we
thought would have the most significant impact on humans, were the most
immediate or critical concerns, or were the most unique solutions to the
current crises faced. And here they are…

Foley et al. offer a framework
to think about the dilemma of future food security and environmental
sustainability on a global scale. They argue that a new agricultural system
must deliver more human value, to those who need it most, with the least
environmental harm. They outlined four food security goals: increasing total
agricultural production, increasing the supply of food (recognizing that
agricultural yields do not always equate with food access), improving the
distribution and access to food, and increasing the resilience of the whole
food system, and four key environmental goals that agriculture must also meet:
reducing greenhouse gas emissions from agriculture and land use, reducing biodiversity
loss, phasing out unsustainable water withdrawals, and curtailing air and water
pollution from agriculture. In the
paper, they summarized and analyzed the potential strengths and weaknesses of
four proposed strategies: stop expanding agriculture, close yield gaps,
increase agricultural resource efficiency and increase food delivery by
shifting diets and reducing waste. This
article was a great comprehensive framework for looking at food and water
issues.

A major
theme throughout the articles was measuring the impacts of climate change on
agriculture. What we found ranged from
new findings on how plant flowering is timed and how these pathways are already
changing in response to small differences in temperature (Kumar et al.), to an article
studying molecular and genetic bases for climate adaption in a plant genome
(Arabidopsis thaliana) (Hancock et al.),
to how in a CO2-enriched world semi-arid grasslands will have improved water
use efficiency, so both soil water content and productivity in the semi-arid
grassland may be higher than previously expected (Morgan et al.).

Lobell et al.
did an econometric analysis of climate trends on crop production (based on the
crops that account for 75% of the calories humans consume) for all countries in
the world. They found negative impacts
globally for maize and wheat production and insignificant impacts on rice and
soybean under climate trends compared to a counterfactual without climate
trends. Since we don’t know how plants will
react to future climate changes this article serves as an initial reference for
how future temperature trends may impact crop output on the global scale.

The
issue of the impact of food production on biodiversity is discussed in Phalan et al.
They compare land sharing (integration of biodiversity conservation and food
production on the same land) with land sparing (separating land for
conservation from land for crops, with high-yield farming) to see which would
do the least harm to biodiversity. The study compared crop yields and densities
of bird and tree species across gradients of agricultural intensity in
southwest Ghana and northern India. The results suggest that in both countries
land sparing would be the optimal strategy.

Another
perspective we thought was important to include is the threat posed by
increased fungal emerging infectious diseases. Fisher et al. calculate that “even low-level persistent disease leads to
losses that, if mitigated, would be sufficient to feed 8.5% of the 7 billion
humans alive in 2011. If severe epidemics in all five crops were to occur
simultaneously, this would leave food sufficient for only 39% of the world’s
population, but the probability of such an event occurring is very low indeed”
(191). Global trade and transportation and
anthropogenic mixing has and will continue to lead to more harmful fungi
strains that jeopardize food security, unless we improve biosecurity the
authors argue.

In both covered journals there were surprisingly few papers dealing with the global water issue. The two most relevant papers in our view deal with reactive Nitrogen as a major source of water pollution, and resilience of water system to environmental disturbance. Holtgrieve et al. studied the accumulation and ecological effects of reactive nitrogen (Nr) using sediments in lakes with minimum anthropogenic impact. The study indicates that atmospheric Nr deposition in remote areas (which has been increasing since preindustrial times), are likely to permeate the biosphere at the hemispheric scale, despite its relatively low rates currently. Davidson et al.focused on interactions between global climate, land use, fire, hydrology, ecology and humans in the Amazon basin. The paper indicates that although the basin-wide impacts of land use and drought may not yet surpass the magnitude of natural variability of hydrologic and biogeochemical cycles, there are some signs of a transition to a disturbance-dominated regime. These signs include changing energy and water cycles in the southern and eastern portions of the Amazon basin.

That
concludes our list. We welcome any
comments or recommendations for other articles that we may have missed.